Re: Is Canon EF 75-300mm f/4-5.6 III too heavy for the EOS M100 ?

The M-Series of bodies not have very good battery life, 200-300 shots per charge, with EF-M lenses. Using EF lenses will only reduce that figure to somewhere under 200, depending on the lens.

I think your suspicion that EF lenses could be too heavy for M bodies is an astute conclusion. I think they are large enough to present a Moment Of Inertia on the lens mount that could exceed the design limits, which is why the Canon EF adapter has a tripod foot built into it.

Anytime the adapter is used with most EF lenses, then you should always support the lens, especially when NOT using a tripod. I have an M3, and it works great with the adapter and Canon’s “pancake” lenses. The EF 40mm and EF-S 24mm lenses.

But, I get the best results with the EF-M 22mm prime, which has the widest aperture in the EF-M lens lineup.

Re: Is Canon EF 75-300mm f/4-5.6 III too heavy for the EOS M100 ?

I would guess it is OK. I doubt it will damage anything no matter how you hold it. The Canon EF 75-300mm f/4-5.6 III Lens is a plastic wonder and weighs in at a pound or so. That shouldn't be any sort of a problem. Your EF-M 18-55mm f/3.5-5.6 IS STM Lens is about 1/2 pound. And if you happen to have the Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens it is 3/4 of a pound or so.

I would guess it is OK. I doubt it will damage anything no matter how you hold it. The Canon EF 75-300mm f/4-5.6 III Lens is a plastic wonder and weighs in at a pound or so. That shouldn't be any sort of a problem. Your EF-M 18-55mm f/3.5-5.6 IS STM Lens is about 1/2 pound. And if you happen to have the Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens it is 3/4 of a pound or so.

While the lens in question does not weigh very much, the adapter moves the CoG, Center of Gravity, further away from the camera body, which increases the Moment of Inertia presented to the lens mount. The further the CoG from the focal plane, the greater amount of torque present on the lens mount.

Canon designed a tripod foot into their EF adapter for a good reason. This works out to be exact opposite of the Inverse Square Law for the drop off in light from a strobe. As distance increases, so does the torque.

I would guess it is OK. I doubt it will damage anything no matter how you hold it. The Canon EF 75-300mm f/4-5.6 III Lens is a plastic wonder and weighs in at a pound or so. That shouldn't be any sort of a problem. Your EF-M 18-55mm f/3.5-5.6 IS STM Lens is about 1/2 pound. And if you happen to have the Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens it is 3/4 of a pound or so.

BTW, a one pound lens is a major problem. Most EF-M lenses weigh in at 1/4 to 1/3 of a pound. Your weights are OFF.

Re: Is Canon EF 75-300mm f/4-5.6 III too heavy for the EOS M100 ?

I have to agree with the comments about buying the 75-300 III to begin with. It's arguably Canon's worst lens, and I would avoid it no matter how cheap it is! Better off with the 55-250 STM if the idea is to get more reach than the EF-M 55-200.

Before leaping into buying a telephoto, my understanding from what I read is that EOS M100 is a cellphone competitor, which does not lend itself to long telephoto use. It does not have a EVF as far as I am aware, so using a longer telephoto hand-held with only two points of support is going to be challenging at best, pretty well demanding it be used with a monopod or tripod to get a stable shooting base. I expect it is a great short to normal range camera, but a long telephoto unit... I would have gone for the M5 or M50 if one had to have a mirrorless body and want to shoot long.

"All the beauty of life is made up of light and shadow", Leo Tolstoy;"Skill in photography is acquired by practice and not by purchase" Percy W. Harris

Re: Is Canon EF 75-300mm f/4-5.6 III too heavy for the EOS M100 ?

I ended up buying a used Canon EF-S 55-250mm f/4.0-5.6 IS Lens for $80.00 and luckily got a very good one. (The seller had a good rating based on previous camera related sales.)

It is hefty enough to put a lot of strain on the camera when not held correctly.

When not hand held, I use the mount on my adapter.

I am very pleased with all aspects and I am getting very nice shots.

I was surprised by the focus speed and how well the IS works. This is my first "adapter" lens (with FotioX adapter).My shaky 77 year old hands have had no problem (although, I admit that I usually used burst mode).

I would avoid using the cheapo Fotodiox adapter ($40) & return it asap because they are not as well built as a genuine first-party EF to EF-M adapter & they may cause compatibility issues or errors to appear on your camera.

Not if but when it breaks up in a matter of time, you may not get 1st party service or support. And eventually, you may end up purchasing a new unit. You will regret it.

Re: Is Canon EF 75-300mm f/4-5.6 III too heavy for the EOS M100 ?

The Fotodiox is working great -good focus/good IS and very good photos. That's all I can ask.

I can buy 5 of them for the cost of one Canon. They are not cheaply built (maybe not as well as the Canon), it works very well, and I bet they outlast me (I am 77 years old).

Unlike a lens, it is not a very complicated mechanism and $200 is a price only a pro or a truely dedicated amateur can stomach. Photography is just one of the many hobbies I enjoy, so I think I made the correct choice.

I did go with a decent Canon lens, because I can see a bad photo immediately.